The present invention relates to rotogravure printing and particularly to the construction and fabrication of printing cylinder assemblies for rotogravure printing.
Rotogravure printing machines generally include one or more image cylinders rotatively driven in nip association with respective platten cylinders. Ink doctored upon the image cylinder surface is applied to the surface of a web or film as the web passes between the ink laden image cylinder surface and the platten surface.
Image cylinder surfaces are created by a number of methods including photo etched rubber or elastomer plates that are wrapped around the perimeter of a structural cylinder surface and bonded in place. Alternatively, an image may be etched into the surface of a metallic shell which is slipped into place axially over a structural carrier cylinder. Additionally, an image may be etched into the surface of a structural cylindrical shell which is secured coaxially about an axle.
Regardless of how an ink transfer image is associated with a rotating cylinder structure, that structure will be supported between axially aligned journals or bearings. Usually, this support will take the form of a solid steel journal shaft or core element which is passed through a structural image cylinder. Such cylinder assemblies are expensive to make and difficult to use, often requiring two or more workmen with hoisting machinery to move and mount the assemblies in the machine frame. Also, the existing structure of print cylinder assemblies does not readily allow print cylinders to be interchanged between different width presses.
It is, therefore, an object of the present invention to provide a print cylinder assembly for rotogravure printing machines.
It is another object of the invention to provide a rotogravure printing cylinder assembly having a materially reduced installation weight.
Another object of the present invention is to provide a print cylinder assembly which permits the same gravure cylinder to be used on different width presses.
Still another object of the present invention is to provide a versatile, lightweight print cylinder assembly which is simple to make and use.
A further object of the present invention is to reduce the storage area required in a rotary printing facility for a given number of cylinders.
An additional object of the present invention is to reduce the inventory of cylinders for a given rotary printing operation using various size presses.
Yet another object of the present invention is to reduce the unit cost of rotary printing press cylinder assemblies.